The present invention relates to key, and in particular, to key for a photoelectric keyboard.
Conventionally, the keys for a keyboard are divided into types of mechanical contact and photoelectric switch, in which instead of the mechanical contact structure the type of photoelectric switch uses photoelectric coupler technology, which uses the principles of optics and the photoelectric coupling technology. Light path is formed by a transmitting element and a receiving element. A light resisting part is proceeded to open and close the light path to change the impedance of the circuit, realizing the on/off of the circuit. The photoelectric switch key is long in lifetime, and small in the change of hand feeling after long time use, compared to other keyboards.
However, the keys of current existing photoelectric switch keyboard suffered from the following disadvantages:
1. As there is no light path collimation and light concentration design between a transmitter and a receiver, the efficiency of photoelectric coupling of the transmitter and the receiver is lower.
2. When dusts are deposited within the key, the sensitivity of the photoelectric coupler is further reduced.
3. The hand feeling of the key is unitary, and the touch sense for the key is not obvious.